The invention relates to transfer switches that transfer electrical power from multiple power sources to a power load.
Transfer switches are used, for example, to automatically and quickly connect an emergency power source to a load when a normal power supply fails. Hospitals use transfer switches to maintain continuous electrical power when a power failure occurs in the electrical utility service to the hospital. When a utility power failure occurs, the transfer switch connects the hospital to a backup power generator without significant interruption of electrical power to the hospital. There is a long felt need for mechanically simple and reliable transfer switches which effectively suppress electrical arcs.